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Harmful Algal Blooms and Animals

Potential Harmful Effects–General

There are potential health impacts, some of them serious or lethal, to people and animals that come in contact with cyanotoxins. Cyanobacteria can disperse throughout or concentrate within the waterbody. Therefore, when a problem is present caution should be used throughout the entire water body and distribution of water sources.


  • Ingesting water with cyanotoxins or mats of cyanobacteria cells
    • Symptoms may include vomiting, lethargy, diarrhea, convulsions, difficulty breathing, and general weakness. There have been livestock deaths from toxic algae exposures and water consumption.


  • In some cases, animals may choose a cyanobacteria source over clean water, even if a clean water source is available. Animals may eat mats of cyanobacteria slime. Therefore, animals should be restricted from cyanobacterica sources and be provided a clean source of drinking water.

The above information applies to agricultural producers and private owners of large animal breeds. For accurate information about pets, please contact your veterinarian or your local county health department for more information.



  • Research has shown that cyanotoxins can bio-accumulate in tissue of aquatic organisms.  The amount of bioaccumulation will depend on the cyanotoxins present, toxin concentrations, exposure length, fish species, as well as other variables.
  • UDAF does not have jurisdiction over aquatic wildlife in public waters.  Wildlife within this state, including aquatic wildlife, falls within the jurisdiction of the Division of Wildlife Resources.
  • UDAF licenses private aquaculture facilities and fee fishing facilities.  If a HAB occurs at an aquaculture facility or fee fishing facility, UDAF could confirm the presence of a HAB, and supply guidance on managing the HAB.